The process by which malignant cells spreads to distant parts of the body, and also refers to the secondary tumours resulting from this process. For example, a cancer of the breast may produce metastatic growths in the glands of the armpit; cancer of the stomach may be followed by metastases in the liver. Metastases are colloquially known as secondaries and their spread occurs through the bloodstream, lymphatic system and across the body cavities. Highly malignant tumours – for example, melanomas – are especially prone to metastasise far and fast. (See CANCER.)